1. Field of the Invention
This application relates to blow-molded containers, and more particularly to round type hot-fillable containers that are constructed to flexibly accommodate volumetric contraction that will occur in response to cooling of product within the container.
2. Description of the Related Technology
Perishable food and beverage products such as fruit juices are typically filled at elevated temperatures, such as 180 to 190 degrees Fahrenheit, under variable pressure conditions into specially designed plastic containers in what is conventionally referred to as the hot-fill process. Container designs that are intended for use with this process are referred to as hot fill type containers. After filling, the containers are sealed, preventing mass transfer into and out of the container. As the product within the containers cools, the volume that is occupied by the product decreases, thereby inducing a partial vacuum within the container that exerts an inward force upon the sidewall of the container. The design of hot fill type containers is heavily influenced by the necessity of managing this shrinkage during cooling. In the past, the shrinkage has most commonly been accommodated by molding one or more concave vacuum panel areas into the sidewall of the container that are designed to deflect inwardly as the product cools. By substantially limiting the deformation to the vacuum panel areas, unwanted distortion of other portions of the container is prevented.
While container designs relying upon vacuum panels have been effective in many ways, certain limitations and disadvantages are associated with their use, including limitations as to the possible variations in the exterior styling of the container, the need to provide enough plastic material to form the vacuum panels with the requisite thickness, and incompatibility with certain types of package labeling processes. For example, it is difficult to use certain types of pressure sensitive labeling on conventional round type hot fillable containers that have prominent vacuum panels.
A need exists for an improved hot fillable container design that obviates the various limitations and disadvantages of conventional hot fill container designs that have concave vacuum panels.